One interesting tidbit I found was the deceased passenger was using a booster seat.
As I regularly fly Mini-Me 1/2 (6 & 7 yrs old) in the RV, I use an inverted booster seat to raise his standard car seat high enough to clear the canopy sill so they can see out. In my case, the car seat is restrained by the standard Vans lapbelt through the approved path, with the aft restraint being picked up by the Vans shoulder harness cable in the baggage area, and the munchkin is in turn strapped securely into his 6 point harness in the car seat. This gives a nice, secure seat and it works well
now but they're rapidly approaching the age where it won't, and this report has given me a bit of thinking to do about the best way to keep them safe...
Originally Posted by The ATSB
The passenger’s seat was found in the fully forward and raised position, and the occupant was seated with a supplemental cushion (also called a booster seat) behind her back and one on the seat base. The United States Federal Aviation Administration (FAA) reported that as supplemental cushions are considered ‘carry-on’ items, they are not regulated.
When the FAA certifies a seat, a specific seat reference point (SRP) is identified, which relates the seat structure to the Anthropomorphic Test Dummy position during certification. If a manufacturer wants to alter the cushion on the seat it must maintain the SRP within an established tolerance, otherwise the seat will have to be re-certificated. When the occupant adds a supplemental cushion it moves them away from the nominal position, which changes how they flail with respect to their surroundings, as well as where their body is relative to the installed restraints.
In this accident, the effect of the supplemental cushions moved the occupant’s body upwards and forwards. This put her at an increased risk of impacting the surrounding structure during the accident sequence. The use of supplemental cushions can also affect the occupant’s vertical acceleration relative to the seat structure increasing the risk of spinal injury. It could not be determined if this alteration from the nominal seating position increased the severity of the injuries sustained. By adding supplemental cushions, a short-statured pilot increases their flail envelope, which increases their injury potential. However, without the supplemental cushion they may have reduced visibility or may not be able to operate the flight controls effectively.